A novel photoelectrochemical immunosensor for N1-methyladenine detection based on BiVO4/g-C3N4 heterojunction with signal amplification of TiO2@NH2-MIL-125(Ti)

Abstract

Photoelectrochemical (PEC) immunosensor was designed to detect N1-methyladenosine (m1A), where BiVO4/g-C3N4 heterojunction was employed as photoactive material, polyamidoamine (PAMAM) and 4-carboxyphenylboronic acid (CPBA) were used as m1A antibody immobilization matrix, and Ti-based metal-organic framework encapsulated heterostructure of TiO2@NH2-MIL-125(Ti) was adopted as signal amplification. Due to the interaction between TiO2 and phosphate, TiO2@NH2-MIL-125(Ti) was captured after immunoreaction between m1A and its antibody, which can further improve the detection sensitivity with increased PEC response. Under optimal experimental conditions, this method presented wide dynamic range (0.05–35 nM) with the low determination limit (16.7 pM, S/N = 3). This detection strategy showed good detection reproducibility, stability and selectivity. This method was applied to assess the effect of antibiotics on m1A content in the leaves, stems and roots of rice seedlings.